As stipulated in institute of electrical and electronics engineers (IEEE) 802.11ac: a basic service set (BSS) is composed of stations (STA) with certain relations within a specific overlay area. In a BSS network, only one central station which full-time manages the BSS, is called an Access Point (AP), and other stations in the BSS network except the AP are called terminals, also known as non-AP STAs.
In a BSS network, the group ID (GID) of the non-AP STA is allocated by the AP in the BSS network, when the AP performs the multi user-multiple input multiple output (MU-MIMO) transmission, the multiple non-AP STAs perform the MU-MIMO transmission in the same Group have the same group ID. Each non-AP STA judges, at the physical layer, that whether the non-AP STA itself belongs to the group according to its GID, if yes, then performs the decoding, if not, then does not perform the decoding, so as to save power of the non-AP STA.
In prior arts, for one BSS network, the group IDs of the non-AP STAs are allocated by the AP in the same network, and for another BSS network, the group IDs of the non-AP STAs in another network are allocated by the AP in the same network, when a non-AP STA belongs to a Group of a BSS network, it owns the GID of the Group. However, when a non-AP STA belongs to two BSS networks (the two BSS networks are respectively BSS1 and BSS2, the access point of BSS1 is AP1, the access point of BSS2 is AP2) at the same time, if a non-AP STA belongs to a Group of BSS1 network, AP1 allocates a GID for the non-AP STA, since BBS2 does not know the situation of GID allocation of BBS1 when allocating GID, there may be a case that the GID allocated by BSS2 and the GID allocated by BSS1 are the same, in this case, for the non-AP STA which belongs to both BSS networks at the same time, a GID conflict exist.